1. Field of the Invention
This invention relates, in general, to an automatic vending machine, and more particularly to an automatic washing apparatus and method for washing an inner part of a drink mixing part. The timing of the washing is dependent on the level of pollution in the inner part.
2. Description of the Prior Art
Automatic vending machines have been widely used in many countries for keeping and dispensing various goods such as coffee, cigarettes, cakes, and candy. The vending machines generally have a transparent chamber for holding the goods, so that users can view the available goods.
FIG. 1 is an inner constructive view of a typical automatic vending machine used for vending beverages such as coffee and tea. As shown in the drawing, the typical automatic vending machine includes a housing 10 that is the external most portion of the vending machine. A source vessel 12 for storing various beverage source materials, such as coffee and tea, is mounted inside the housing 10. A source supply part 5 supplies the beverage source material stored inside the source vessel 12. A source shoot 14 is mounted at a lower side of the source supply part 5, for guiding the movement of the beverage source material from the source supply part 5. A hot water supply part 6 supplies hot water. A drink mixing part 7 mixes the beverage source material guided through the source shoot 14 and the hot water supplied from the hot water supply part 6.
FIG. 2 is a schematic block diagram of a typical automatic beverage vending machine. As shown in the drawing, the automatic vending machine includes a coin detecting mechanism 1 that provides a signal according to the amount of the coins inserted in the vending machine. The automatic vending machine further includes a goods selecting part 2 for selecting an article from the available goods, and a control part 3 for generating a control signal to display the status of the goods related to the amount of the coins inserted, as detected by the coin detecting mechanism 1. The control part 3 further controls the supply of the beverage source material and hot water needed for the goods as selected from the goods selecting part 2. A display part 4 is included for displaying the total amount of coins inserted and the status of the automatic vending machine. Also included is a source supply part 5 for supplying the beverage source according to a signal from the control part 3, a hot water supply part 6 for supplying the hot water, and a drink mixing part 7 for mixing the beverage source material supplied from the source supply part 5 and the hot water supplied from the hot water supply part 6. The mixed beverage is extracted through a nozzle that is part of mixing part 7.
Additional details regarding the goods selecting process and operating process of conventional automatic vending machines will be explained hereinafter.
When currency, such as coins and bills, is inserted through a inserting slot (not shown), the condition of the coins or bill and the value of coins or bill is detected by a plurality of sensors (not shown) of the coin detecting mechanism 1, and a signal is provided to the control part 3. The control part 3 generates a signal for display part 4 to display the total inserted amount according to the signal from the coin detecting mechanism 1. The display part 4 displays the selection possibilities according to the control part 3, such as when the total inserted amount of coins exceeds the price of the goods available from the automatic vending machine.
After the selection availability shown in the display part 4 has been displayed, a selecting button is pushed by the user, which causes the selected goods to be extracted from the automatic vending machine. A signal corresponding to the goods selected is provided to the control part 3. At this time, control part 3 generates a control signal to supply the beverage source material and hot water corresponding to the goods selected by the user, and to mix the beverage source material and the hot water.
Accordingly, after the beverage source material has been supplied from the source vessel 12 through the source supply part 5 by a signal from the control part 3, the beverage source material is supplied to the drink mixing part 7 through the source shoot 14. Simultaneously, hot water is supplied from the hot water supply part 6 to the drink mixing part 7 according to a signal from the control part 3.
Subsequently, after the beverage source material from the source vessel 12 and the hot water from the hot water supply part 6 has been mixed in the drink mixing part 7, the mixed beverage is extracted through the nozzle and presented to the user.
However, a problem exists in the above automatic vending machine in that all of the beverage mixed in drink mixing part 7 is not extracted from drink extracting part 8. A portion of the beverage remains in the drink mixing part 7, resulting in an inner part of the drink mixing part 7 being polluted, thereby causing a unsanitary state of the automatic vending machine. Further, maintenance of the vending machine is inconvenient because it requires manually washing the inner part of the drink mixing part.